Crayola, the colored pencil and crayon maker that dominated the artistic phase of countless childhoods, is focusing on helping adults relax with a new line of coloring books.

Crayola’s new “Color Escape” line of adult coloring books is reaching out to the growing adult market. The line has a range of coloring options, from nicer 11x17 illustrations by artist Claudia Nice to four different 8x10 color books illustrated by the artists of Hallmark. Style options include illustrations that are geometric, kaleidoscopic, nature scenes, or garden-themed. All of the options are designed to offer “a soothing, creative experience that’s easy to do and easy on your mind,” according to Crayola’s website.

Beyond the illustrations, Crayola is also marketing the tools. One box of 12 fine-line markers are exclusive to nature, geometric, and kaleidoscopic themes. A different set of watercolor pencils are exclusive to the garden-themed illustration set. While an industry of adult coloring books might have sounded like something that could only exist in a cartoon a few years, many adults are buying into the stress-relief alternative.

Adult coloring books are sweeping the world in popularity. Amazon’s top 20 bestseller list contains four adult coloring books, and the IndieBound best seller list has listed The Mindfulness Coloring Book, by Emma Farrarons, in its top 10 for months. However, the popularity was not foreseen by marketing executives or a clever boardroom ploy. The books began with an inauspicious and uncertain start.

“I thought my mom was going to have to buy a lot of copies,” Johanna Basford, who illustrated one of the first adult coloring books to be published, "Secret Garden," told The New York Times. “When the sales started to take off, it was a real shock.”

"Secret Garden" was published in March 2013. By August, it had sold over 6.8 million copies world-wide, with over 3 million sold in China.

Rather than gape at the coloring books’ surprising popularity, companies are jumping in to build a market in the new niche. Barnes and Noble on Saturday is launching their All-American Art Unwind event, inviting adults to come together and color. In addition to launching the "Color Escape" line, Crayola,has partnered with Brit + Co to produce a crowdsourced coloring book for adults, illustrated by over 50 different artists.

“For over 100 years, Crayola has provided children an opportunity to unleash their imaginations and bring their creations to life,” said Kim Rompilla, a marketing director at Crayola, told Business Wire. “This partnership is a terrific opportunity for Crayola and Brit + Co to show our belief that everyone is creative.”